It's a terrible passive. With 4 players in a group you're looking at 3 extra seconds in base werewolf transformation. The benefit below that becomes minuscule and is a waste of skill points.
The whole notion of tying a passive to having other werewolves around is silly, as in a group composition no tank or healer will go werewolf since it replaces their role specific skills (werewolves cant heal, and werewolves can't taunt or have decreased damage from blocking or shield bash), so at best you're looking at 2 DPS going werewolf.